I recently created a technic pack for a server that I help manage. While testing it I noticed that it is just making a file in the modpack directory called what the name of the file was with everything in it instead of moving them into the bin, mods, and config folder within the pack. This causes it to launch a unmodded version of minecraft.
Here is the pack if you would like to see this for yourself.
http://www.technicpack.net/modpack/details/lualand-modpack.509613